Powershift transmission for agricultural machines

Abstract

A powershift transmission for an agricultural machine includes a transmission housing, an input shaft unit and an output shaft, wherein the input shaft unit and the output shaft extend at least in sections within the transmission housing. An auxiliary shaft is arranged parallel to but offset between the input shaft unit and the output shaft. The input shaft unit and the auxiliary shaft are connected to one another via a front-mounted range unit, and the auxiliary shaft and the output shaft are connected to one another via a rear-mounted range unit. The front-mounted and rear mounted range units each includes at least two gear wheel pairs, the at least two gear wheel pairs being individually coupled or decoupled. The auxiliary shaft unit includes a first auxiliary shaft and a second auxiliary shaft, where the first and second auxiliary shafts are coupled to one another via a reduction gear unit.

The invention claimed is: 
     
       1. A powershift transmission for an agricultural machine, comprising:
 an input shaft; 
 an output shaft arranged parallel and offset to the input shaft; 
 a first auxiliary shaft arranged next to and coaxial with a second auxiliary shaft, the first and second auxiliary shafts arranged parallel and offset between the input shaft and the output shaft; 
 a front-mounted range unit including four individual gear wheel pairs connecting the input shaft and the first auxiliary shaft, the four individual gear wheel pairs being coupled or decoupled via a first plurality of clutches having two clutches arranged on the input shaft and two clutches arranged on the first auxiliary shaft, the front-mounted range unit including four shifted states; 
 a reduction gear unit connecting the first auxiliary shaft and the second auxiliary shaft, the reduction gear unit including a first reduction-gear-unit gear wheel pair and a second reduction-gear-unit gear wheel pair; and 
 a rear-mounted range unit including four individual gear wheel pairs connecting the second auxiliary shaft and the output shaft, the four individual gear wheel pairs being coupled or decoupled via a second plurality of clutches having two clutches arranged on the second auxiliary shaft and two clutches arranged on the output shaft, the rear-mounted range unit including four shifted states; 
 wherein in a first shifted state of the reduction gear unit, the first auxiliary shaft is coupled directly to the second auxiliary shaft so that both transmitted torque and rotational speed remain unchanged between the first auxiliary shaft and the second auxiliary shaft; 
 wherein in a second shifted state of the reduction gear unit, the first auxiliary shaft is connected to the second auxiliary shaft via the first reduction-gear-unit gear wheel pair and the second reduction-gear-unit gear wheel pair so that transmitted torque increases and rotational speed decreases; 
 wherein in the first shifted state and the second shifted state of the reduction gear unit, the input shaft and the output shaft rotate in a first direction, and the first auxiliary shaft and the second auxiliary shaft rotate in a second direction opposite the first direction; 
 wherein the front-mounted range unit defines a first shift level, the reduction gear unit defines a second shift level arranged downstream of the first shift level, and the rear-mounted range unit defines a third shift level arranged downstream of the second shift level; and 
 wherein the powershift transmission includes thirty-two gearshift variants. 
 
     
     
       2. The powershift transmission of  claim 1 , wherein the rotational direction of the main output shaft is reversible by a reversing unit. 
     
     
       3. The powershift transmission of  claim 2 , wherein the reversing unit is integrated into the reduction gear unit.